minipush is a RESTful Comet server that does not use any JavaScript libraries. It allows developers to create real-time Web applications easily using their favorite programming languages, such as PHP or Ruby.

Zbatery is an HTTP server for Rack applications on systems that either do not support fork(), or have no memory (nor need) to run the master/worker model. It is based on Rainbows! (which is based on Unicorn (which is based on Mongrel)) and inherits parts of each. Zbatery supports your choice of all the thread/fiber/event/actor-based concurrency models and Rack middleware that Rainbows! supports (or will ever support) in a single process. Zbatery will still exploit certain features of Unix for transparent upgrades, log reopening, and graceful stops, but does not rely on them for basic functionality.

ICEfaces is a framework for developing Ajax applications for the Web and iPhone in Java with JavaServer Faces. In contrast to typical Web applications, ICEfaces applications can update any part of the page at any time. Full page refresh is eliminated, and multi-user interaction is supported through AJAX Push.

WACS (pronounced "wax") is a full Comet server that is extremely tiny, fast, and permits you to serve push requests as well as normal Web server requests for simple files. It also contains a proxy to a more full-featured Web server.

Kometka is a JavaScript and PHP library for making AJAX programs whose instances communicate with each other. The communication server is written in PHP and the communication clients are written in JavaScript. When one client sends a message to the server, the server pushes that message to all clients (using the comet technique). With this library, you can write chat programs, multiplayer online games, and more.